Perifosine inhibits biofilm formation of Pseudomonas aeruginosa by interacting with PqsE protein / 中华预防医学杂志

To explore the biofilm inhibitory efficacy of perifosine against Pseudomonas aeruginosa (P. aeruginos) and its mechanisms. Twenty-fourwell plate was used to form biofilms at the bottom and crystal violet staining was used to determine the biofilm inhibitory effects of perifosine against P. aeruginosa, the wells without perifosine was set as control group. Glass tubes combined with crystal violet staining was used to detect the gas-liqud interface related bioiflm inhibitory effects of perifosine, the wells without perifosine was set as control group. Time-growth curved was used to detect the effects of perifosine on the bacteial planktonic cells growth of P. aeruginosa, the wells without perifosine was set as control group. The interaction model between perifosine and PqsE was assessed by molecular docking assay. The inhibitory effects of perifosine on the catalytic activity of PqsE was determined by detection the production of thiols, the wells without perifosine was set as control group. Binding affinity between perifosine and PqsE was detected by plasma surface resonance. The biofims at the bottom of the microplates and air-liquid interface were effectively inhibited by perifosine at the concentration of 4-8 μg/ml. There was no influence of perifosine on the cells growth of P. aeruginosa. The resuts of molecular docking assay indicates that perifosine could interacted with PqsE with the docking score of -10.67 kcal/mol. Perifosine could inhibit the catalytic activity of PqsE in a dose-dependent manner. The binding affinity between perifosine and PqsE was comfirmed by plasma surface resonance with KD of 6.65×10-5mol/L. Perifosine could inhibited the biofilm formation of P. aeruginosa by interacting with PqsE.

Effects of Serum and its components on the biofim formation of Pseudomonas aeruginosa / 临床检验杂志

Objective@#To study the effects of serum and its components on biofilm formation of Pseudomonas aeruginosa. @*Methods@#96 well microplates combined with crystal violet staining was used to detect the effects of serum, albumin and transferrin on biofilm formation of Pseudomonas aeruginosa. And confocal laser scanning microscope was used to observe the morphology of the biofilm. @*Results@#The biofilm of PAO1 was significantly enhanced from 2.26±0.42 to 3.42±0.08（t=4.71, p<0.01）with horse serum and but reduced to 0.807±0.10（t=4.71,p<0.01） by human serum; And the total biofilm biomass was significantly increased and clump-changed with horse serum, but decreased and scattered in distribution by human serum. Besides, horse serum could also enhance the biofilm formation of part of the clinical isolates of Pseudomonas aeruginosa, however, human serum could inhibit the biofilm formation of all of the clinical isolates. And 2.5g/L albumin could significantly enhance the biofilm of PAO1 from 1.96±0.22 to 2.54±0.18（t=3.55，p<0.05）, but 5 g/L could reduce the biofilm of PAO1 from 1.85±0.36 to 0.84±0.24（t=4.03，p<0.05）.@*Conclusion@#Horse serum and albumin could significantly promote the biofilm formation of Pseudomonas aeruginosa, but human serum and transferrin could decrease its biofilm formation.